This is the final piece that brings us around, back to the beginning. We covered some of this territory before, back in Episode 2, but at the time, it was hard to explain that Parikshit was Arjun's grandson and that Takshaka had an ancient feud with the dynasty going back to the fire at the Khandava Forest. Also, back then we were anxious to get going with the story itself, and all the digressions with angry brahmins and talking snakes only made things confusing at the time.
So now we have re-visited the beginning at our leisure, and now you know the circumstances in which the Mahabharata was first publicly recited. The burnt snake guts must have still been warm when Vyasa's disciple Vaishampayana began the tale.